The Aluminum used is a wide range of spherical aluminum. The actual mesh size ranges from 40-325. Gives a nice golden tail with bright silver mixed in. Cheap formula, MgAl can be left out if not available for a straight gold glitter. Other mesh sizes of MgAl can be used for different hang times on the silver part of the glitter.
If all components are fine powder, milling is not needed. If milling is needed, ball mill the BP components and Sodium Bicarbonate for 20-40 minutes and then screen in the metal components